1. Field
This disclosure relates to a polyurethane foam composition and a polyurethane foam prepared using the same.
2. Description of the Related Art
Polyurethane foam has an excellent adiabatic effect, and it is widely used as a heat insulating material (e.g., for buildings and refrigerators/freezers).
Polyurethane foam is a soft or rigid porous polyurethane formed by mixing and reacting isocyanate and polyol with a blowing agent, a catalyst, a surfactant, a nucleating agent and other additives, and gasifying the blowing agent with heat generated from the reaction.
Conventional blowing agents are chlorofluorocarbon (CFC)-based materials. Such materials, however, have a low boiling point, often near room temperature, and they are readily evaporated by the heat generated from the reaction of isocyanate and polyol. As a result, they are environmentally polluting materials that not only destroy the ozone layer of the atmosphere but also contribute to the greenhouse effect, and the use of chlorofluorocarbon-based materials is now prohibited by the Montreal Protocol and the Kyoto Protocol.
Accordingly, the household electronic appliance industry and freezer container manufacturers have selected hydrofluorocarbon (HCFC)-based materials, e.g., HCFC-141b or cyclopentane, for use as blowing agents, substituting for the CFC-based materials in mass production. However, these materials tend to have higher vapor thermal conductivity than the chlorofluorocarbon-based materials. Since vapor thermal conductivity is the main factor affecting the thermal conductivity of polyurethane foam (i.e., vapor thermal conductivity is more significant than solid-phase (matrix) or radiation thermal conductivity), the polyurethane foam and application equipment manufactured using the substitute blowing agents have been found to exhibit poor adiabatic performance.
In addition, although the ozone depletion potential (“ODP”) of hydrofluorocarbon-based materials may be lower than that of the chlorofluorocarbon-based materials, their ODP is not zero, and the hydrofluorocarbon-based materials are already listed as regulatory materials in the European Union (EU) countries, Hydrofluorocarbon-based materials further exhibit high global warming potential.
As a result of the problems associated with hydrofluorocarbon-based blowing agents, cyclopentane is drawing attention as a potential blowing agent that minimally affects the ozone layer and global warming. However, the vapor thermal conductivity of the cyclopentane is relatively high, at 0.0128 W/m·K, and polyurethane foam manufactured using cyclopentane has needed to be thick in order to provide sufficient thermal insulation. There is thus a need in the art for polyurethane foam compositions that improve the insulating performance of polyurethane foam produced therefrom.